Off products

Good day Yesterday I purchased two Fat Free strawberry drinking yogurts (300 ml) from Woolworths La Lucia Mall Durban. The expiry says 15/03/2018 but the product is already off and exploded on my desk at work. I have since thrown away the slips for both. I have had no response from Woolworths on this after phone calls and emails. I am very disappointed in this product and will be reluctant to buy it again. This quality of product is not acceptable especially as a marketed premium product. This is not the first time this particular product has been off, I have also had the same experience with their fat free yoghurts.